Electric switch



Sept. 8, 1925;

G. A. BURNHAM ELECTRIC SWITCH 2 Sheets-Shoot 1 Sept. 8, 1925.

G. A. BURNHAM ELECTRIC SWITCH Filed March 22. 1921 2 Sheets-Shed 2 Patented Sept. 8, 1925.

UNITED STATES NPMENT OFFICE.

GEORGE A. BURNHAM, OE SAUGUS, 1a..SSACIIUSETTS,` ASSIGNOR, BY MESNE ASSIGN- MENTS, To CONDIT ELECTRICAL MANUFACTURING COMPANY, A CORPORATION OF MASSACHUSETTS.

ELECTRIC SWITCH.

Application filed `March 22, 1921. Serial No. 454,427.

To all whom t may Concern. y

Be it lnown that I, GEORGE A. BURNHAM, a citizen of the United States, residing at Saugus, in the county oil Essex and State of Massachusetts, have invented an Improvement in Electric Switches, ot which the following is a specification.

This invention relates to electric switches of the type having an inner Oil receptacle and an outer spill receptacle, as set forth in my Patent No. 1,413,156, dated April 18, 1922.

In an electric switch of the type above set forth Oil may be expelled from the inner receptacle under sufficiently severe circuitin terrupting conditions and collect in the outer or spill receptacle; and the oil level will be lowered in the inner receptacle and raised in the outer receptacle.

An object of this invention is toA return oil to the inner receptacle from the outer recep tacle subsequent circuit interruption and restore the oil level therein to the normal level whereby the .switch may be at all times in a state oi' maximum circuit-interrupting eftectiveness.

The switch embodying the invention may be provided with communicating 'passages extending between the outer and inner receptacles below the oil level therein and preterably at the lower portions of said receptacles arranged to admit a flow of oil 4trom said outer into said inner receptacle when the oil level in the outeris higher than in the inner receptacle, thereby to replenish oil ex` pelled from said inner into said outer recep` tacle upon circuit interruption, and restrict the `flow of oil from said inner to said outer receptacle through said passages due to a momentarily elevated pressure in said inner receptacle during the period of Circuit interruption.

A further object is generally to improve the construction and operation Otan electric switch. 1

Certain features of this invention are disclosed in my co-pending application Serial No. 390,850, filed Jun@ 22, i920.

Fig. 1 is a side elevation of an electric switch embodying the invention.

Fig. 2 is a plan view of the switchof 1. Fig. 3 is a transverse vertical section of the switch.

View of a valve member.

top thereof.

Fig. 5 is an enlarged sectional detail along line 3--3 ot' Fig.` 1 illustrating the opening through the wall of the inner receptacleand the valve member controllingsaid opening.

'6 is a detail similar to Fig. 5 illustrating the valve open with a higher level of oil in the outer than in the inner receptacle thereby to admit a flow of oil from said outer into said innerreceptacle.

Fig. 7 is a transverse sectional elevation ot the'inner and outer receptacles with a modi iied form of oil communicating passages therebetween. Y

` Fig. 8 is an enlarged detail illustrating the oil'passages of Fig. 7

As here shown, the switch embodying the invention includes the switch frame 10 having the inner oil receptacle 11 and the outer spill receptacle 12 Aenclosing Said inner recepy YSaid trame is formed with the inner depending flange or apron '19 which surrounds and is peripherally spaced from the upper portion of the side wall thereof to provide a passage a over the top of said inner receptacle down the side wall thereof into the outer receptacle; and said rods 14: may be provided with stop members 2O which serve to hold the inner receptacle spaced below the inner face of the switch traine thereby to form a permanent gas vent passage over the top of the inner receptacle. Said apron extends downward over the outer face of the side walls of saidinner receptacle a substantial distance whereby to support the. side walls and guidey the gas andfoil expelled from the inner receptacle into the outer receptacle at a substantial distance below the Said outer receptacle isspaced `from said inner receptacle to provide an annular chamber b in which to receive the gas and oil and Olrvapor expelled fromv the inner receptacle and collect the Oil. Said switch frame is also formed with a second and outer depending flange or apron :2l Whirl? extends downwardly over yand is closely spacedy from the upper portion` of the side walls of said outer receptacle; and gas expelled from the inner' receptacle inally passes over the top of the outerv receptacle through the passage c between said outer receptacle and apron into the atmosphere in a downward direction. 'Yliilewfthe inner oil receptacle may be held against the inner face of the switch frame by the springs 15, the top of the outer receptacle is preferably spaced below said switch frame to provide a passage therebetween; and there may be a passage .over the 4top ofthe .inner oil receptiule 4 while in .contact .with the switchy frame by reason of irregularities in the. lower face of the switch frame. For

. somewpurposes the outerv ange `2l may `be omitted, however.

The lower portion of thesidetwall ofthe Y inner receptace 11 may bei formed with apertures 22 thereinto provldeoil communicating passages between the outer and inner receptacles; and the wall at theedge of the f aperturesfmay be inturned to vform a seat 23 for a check valve.4 as inkFigs. 3 and 5. yEach of said apertures is adapted to be .closed during circuit vinterruption by a ,vali/'e242 vdisposed within the innerreceptacle-and pivotally suspended from a pin 25 carriedfby the bracket'QG secured to the side wall of the receptacle above .the aperture. i Prefer 1 ably, the pin recess 24:91u said valve is somewhat larger than the pin 25. whereby to fa` cilitate the seating of the valve. ISaid valves -function as check valves to admita How of oil. from the outer into the inner receptacle when the oil level in theouter is higher than in said inner receptacle but prevent a flowof oil from said'inner to. said outerrcceiitacle.

It is-not essential that saidvalves bei strictly voil tight as a slight leakage of oil'thercthrough from the inner to `the outer recepswitch, `whereby thecurrent interrupting capacityof vtheswitch may be enhanced, and

to provide a relatively deep expansion chamber fabove the oil in said outer receptacle in which; to `condense oilvaporiand collect oilfdischarged therein' from said inner receptacle without the discharge of `substantial lquantities of oilffrom the .outer .receptacle into. theV atmosphere. i Said valves A24; may normally .be closed or they .mayi .be ,'open.

' Upon circuit einterrupft'ion, conditions within the inner receptatle may ,be such. as to,l increase the.A pressure: 'thereinA and cause the expulsion .ofgas andioil vapor and liquid .oillinto the. outer receptacle, The gas will finally escape from theouter receptacle. to the atmosphere while thegreater part of the Aoil vapor will condense and, with the liquid oil, collect in the outer receptacle and raise Athe oil level therein above that'in the inner receptacle; and the oil level in the inner rel, .ceptacle will be lowered by reason oill loss of oil therefrom. During the period of elevated pressureinpthe inner receptacle the valves 24 will be forced and held against their seats thereby to prevent an appreciable flow of oil from the inner to the outer receptacle. .lVhen the pressure within the inner recep- Y tacle is reduced substantially to atmospheric the higher head of oil in the outer receptacle will operate to force said valves 2l open and permit a flow of oil from the outer into the inner receptacle until a quantity of oil equivalent to ,that expelled from the inner to the outer receptacle has beendelivered or restored to the inner receptacle and the level of oil in both receptacles is again at substair tially thesame level. vIn this manner cil expelled from the ,inner oil receptacle under conditions resulting from circuit interruption will be automatically restored. to the inner-receptacle .and consequently the necessity for frequent replenishing of oil niark I ually to the inner receptacle is obviatet .It is not essential that the communicating passages between the outer and inner recep- .j tacles be closed .by valves during circuit interruption. In Figs. 7 and 8, a construction is illustrated wherein valves are. unnecessary. As shown in these figures the coinmunicatingpassages 22 in the side wall or the inner receptaclearo of relatively small and thereby restricted cross-section. lith this arrangement, but a small amount of oil will be'forced from the inner into the cuter receptacle vduring circuit interruption for the reason that the period of duration of ele- `vated pressure in the inner receptacle during circuit interruption is relatively short.

There mayE be av relatively long period of` time between two successive operations of Vtheswitch to; interrupt the circuit and this time usually is ample for `the flow of oil `Athrough saidsmall passagesy from the outer into the inner receptacle to restore the normal oil level in said inner receptacle. The switch may also be so arranged as to permit va plurality of rapidly repeated operations without detrimental reduction of-oil in said inner receptacle and loss of oil into the at-y .mosphere from said outer receptacle by providing the inner oil receptacle with suiiirieit oil capacity.

The term outer and inner receptacle :is 1herein intended -to include any construction wherein two oil containing compartcments aleyprovided, in oneof Vwhich the switch members are adapted to be contained and which isarranged to. vent into the other compartment.

llo

mman.

Itis to be noted that the construction and arrangement of the switch trame and oil receptacles provides oil separator apparatus wherein the oil-laden gas is given centrifugal motion as it passes upwardly about the lower edge of the flange 19, with the result that the oil is projected out of the gas stre-am into the relatively dead gas space above the oil level in the outer oil receptacle,

It is obvious that the invention may be incorporated in other modified structures without departing from the spirit thereof.

I claim:

1.fAn electric switch having an oil receptacle freely vented above the oil level therein, and self-contained means to catch oil eX- pelled `from the receptacle through the vent and subsequently return the oilto t-he receptacle beneath the oil level therein.

2. An electric switch having a switch frame, inner and outer oil receptacles disposed beneath said frame and both adapted normally to contain oil to the same level, said inner receptacle arranged to vent vinto said outer receptacle above the oil level, and means to return to the inner receptacle oil expelled from said inner to said outer receptacle through said vent.

3. An electric switch having a switch frame, inner and outer oil receptacles disposed beneath said frame and both adapted normally to contain oil to the same level, said inner receptacle arranged to vent into said outer receptacle above the oil level, and an oil passage connecting said outer and inner receptacles adapted to return to the inner receptacle oil expelled from said inner into said outer receptacle through said vent. A

4. An electric switch having a switch frame, inner and outer oil receptacles disposed beneath, said frame and both adapted normally to contain oil to the same level, said inner receptacle arranged to vent into said outer receptacle, an oil passage connecting said outer and inner receptacles adapted to return to the inner receptacle oil expelled from said inner into said outer receptacle through said vent and a valve arranged to govern the direction of flow of oil in said passage.

5. An electric switch having vinner and outer oil receptacles both adapted normally to containoil to .the same level and a free vent passage connecting said two receptacles above the oil level therein, said switch adapted to `expel oil from said inner recepi tacle through said vent passa-ge into said outer receptacle and raise the oil level therein, and means to equalize the oil level in said receptacles.

6. An electric switch` vhaving inner and outer oil receptacles both adapted normally to .contain oil to the same level and a free vent passage connecting said two receptacles abover the oil level therein, said switch adapted to expel oil from said inner-reeptacle through said vent passage into said outer receptacle and raise the oil level therein, and means to equalize the oil level in said receptacles comprising an. oil passage in communication with the oil spaces ot said receptacles below the oil level there- 1n.

7. An electric switch having inner and outer oil receptacles both adapted normally to contain oil to the same level and a vent passage connecting said two receptacles above the oil therein, said switch adapted to expel oil from said inner receptacle through said vent passage into said outer receptacle and raise the oil level therein, and means to equalize the oil level in said receptacles comprising a valve-controlled oil passage in communication with the oil spaces of said receptacles below the oil level there- 8. An electric switch having a switch frame, inner and outer oil receptacles disposed below said frame both adapted normally to contain oil to the same level, a vent passage connecting said receptacles -above the surface of the oil therein, an oil passage connecting the oil spaces of said `receptacle below the surface of the oil therei in, and a check valve arranged to close said passage against flow of oil from said inner into said outer receptacle and to open said passage for flow of oil from said outer into said inner receptacle.

9. An electric switch having a switch frame, inner and outer oil yreceptacles disposed beneath said frame both adapted nor- Vmally to contain oil to the same level, a free vent" passage connecting `said `receptacles" A above the oil therein, and means actuated by a difference in oil level in said receptacles to neutralize the difference in oil level in said receptacles.

10.An electricswitch having a switch frame, inner and outer oil receptacles disposed beneath said frame both adapted normally to contain oil to the same level, a vent passage connecting said receptacle above the oil therein, and means comprising a valve actuated byian elevated oil level in said outer'receptacle to admit oil from said i inner receptacle. f

1l. An electric switch comprising a switch frame, an oil receptacle having outer and inner oil compartments disposed below said frame, said inner compartment having a vent into saidouter compartment, said receptacle having an oil passage inthe lower portion of the wall of the inner compartment arranged to provide oil communication between the compartments and a check valve in said inner compartment arranged to close said passage against flow oioil from said inner' into said outer compartment,

12. An electric switch having inner and outer oil receptacles with peripherally spaced side walls, a switch iti-ame comprising a cover for said receptacles having an inner depending apron peripherally enclosing and closely spaced trein the side wall of said inner receptacle whereby to provide a vent passage from said inner receptacle over and down the side wall thereof into said outer receptacle and an outer depending apron peripherally enclosing and closely spaced from the side wall of said outer receptacle whereby to provide a vent passage-trom said outer receptacle over and-'down the side wall thereof into the atmosphere.

13. An electric switch having inner and outer oil receptacles with peripherally spaced side walls, a switch traine comprising a cover for said receptacles having an inner depending apron peripherally enclosing and closely spaced from the-side wall of said inner receptacle whereby to provide a vent passage from said inner receptacleover and down the side wall thereof 4into said outer receptacle and an outer depending apron peripherally enclosing and closely spaced from the side wall of said outerreceptacle whereby to providea vent passage from said outer receptacle over and down the side wall thereof into the atmosphere, the lower portion ot the side wall of said inner receptacle having an opening therein communicating with the oil space in said outer receptacle, and a check valve in said inner receptacle arranged to cover said opening.

14. An attachment for an electric switch con'iprising` outer and inner oil receptacles, the lower portion of the side wall. of said inner receptacle having a uni-laterally conducting oil passage therethrough arranged to establish communication with the oil spacesin said receptacles.

15. An attachment for an electric switch comprising outer and inner oil receptacles, the lower portion of the side wall of said .inner receptacle having an oil passage therethrough arranged to establish communication with the oil spaces in said receptacles and a check valve in said inner receptacle arranged to cover said opening and open toward the interior of said inner receptacle.

16. An electric switch including a casing having two compartments adapted to contain f oil, a free gas vent connecting said compartments above the oil level, stationary and movable switch members contained in one of said compartments, and a restricted oil passage arranged to establish communication between said compartments belowthe oil level therein.

17. An electric switch including a casing having two compartments adapted to contain oil, and stationary and movable switch mem- :bers contained in one of said compartments, said casing havingauni-directionally restricted oil passage arranged` to establish communication between said compartments below the oil level therein.

klevel therein arranged to establish oil equilibrium in said compartments and restrict the How of oil from said switch member containing coiiipartineiit into said other compartment under circuit-interrupting conditions.

19. An electric switch having the combination olI open top and closed bottom inner and outeri'eceptacles both adapted to contain oil normally to the same level and aI free vent` passage connecting said two receptacles above the oil level therein, said switch adapted to expel oil from said inner receptacle through said vent passage into said outer receptacle and raise the oil level therein, relatively movable switchinembers depending downward into the oil in said inner receptacle,.and means to equalize the oil ,level in said receptacles comprising an oil passage in communication with the oil spaces of said receptacles below the oil level therein.

20. -An oil switch having an oilv receptacle including an oil space and a gas space, a. vent to the atmosphere extended Jfrom the gas space, and a separator device in said vent and including a second oil receptacle surrounding said vent, said device ai'- ranged to separate oil from thel stream passing through it ,and deposit the separated oil in said second receptacle, said second receptacle having means independent of saidvent to return the separated oil to the oil receptacle belowthe oil level therein.

21. An. oil v receptacle for an electric switch constructed and arranged to provide an` oil-containing` compai-tnientiand an oilcatching compartment both arranged 'for intercommunication at the upper portions thereof, said oil-catcliing compartment having a bottom sealedagainst passage ot gas but open for passage of oil therethrough into said oil-containing compartment.

22. An oil receptacle for an switch constructed and arranged to provide an oil-containing compartmentl and an oilcatcl'iing compartment both arranged for intercommunication at the upper portions thereof, said oil catchingcompartment having a bottom sealed against passage. of gas but open for .passage of oil therethrough linto said oil-containing compartment, and

a single cover lfor both compartments.

.23. .An .electric switch having two. comelectric 1 partments, one of said compartments arranged to contain oil and the switch members and vent into the other' compartment above the oil level, said last compartment arranged to vent into the atmosphere, and means to maintain approximately the same oil level in Yboth compartments.

Q4. An electric switch having two compartments, one of said compartments arranged to contain oil and the switch members and vent into the other compartment, said last compartment arranged to vent into the atmosphere, means arranged to maintain approximately the same oil level in both compartments, a cover for both compartments, and means admitting of a relative movement between said cover and compartments due to gaseous pressure within the switch.

25. An electric switch comprising a casing having an oil receptacle and a cover therefor, and means contained within the casing and below the cover arranged to provide an oil catching compartment having a passage at the top thereof in communication with the receptacle above the oil therein, and delecting means arranged in the path ot the gas stream through said passage and a passage at the bottom thereof arranged to provide oil communication with said oil receptacle below the oil level therein.

26. An electric switch comprising a cas-- ing having an oil receptacle and a cover therefor, and means contained within the casing and helow the cover arranged to provide an oil-catching compartment having a passage at the top thereof in communication with the receptacle above the oil level therein, and a flange carried by the cover below the top thereoll arranged to ydeflect downwardly into said compartment gas passing through said passage, and means independent of said passage to return oil from said oil-catching compartment into the oil receptacle.

27. An electric switch comprising a casing including an oil receptacle and a cover therefor, means to provide a compartment under the cover, means to provide a gas entrance and a gas exit at the top of the compartment, means to direct downwardly toward the bottom of the compartment gas passing through said gas entrance, and means to return oil from said compartment into the oil receptacle.

28. An electric switch having an oil receptacle constructed and arranged to provide an oil-catching compartment, said compartment having an open top, a cover for said receptacle and compartment, a plate spaced from the side walls of and extended downwardly into the top of said compartment, and means to return oil from said oil-catching compartment into said oil receptacle. i

29. An electric switch having an oil receptacle constructed and arranged to provide an oil-catching compartment in the upper portion thereof, said compartment having an open top, a cover for said receptacle and compartment having a flange extended downwardly over and spaced from the inner wall of and into the top o said compartment, means to conduct oil from said oil-catching compartment to said oil receptacle, and means yieldingly to lsupport the cover in such relation.

In testimony whereof I have signed my name to this specilication.

GEORGE A. BURNHAM Cri 

